Clamp for master sheets of printing machines



NOV. 16, 1948. L" MORSE 2,453,927

CLAMP FOR MASTER SHEETS OF PRINTING MACHINES Filed Oct. 2, 1943 3 Sheets-Sheet 1 INVENTOR.

LAWRENCE H. Home 6 410, 73M, V27 101m i 91 flrramm! Nov.' 16, 1948. L. H. MORSE cum? FOR MASTER SHEETS 0F PRINTING MACHINES 3 Sheets-Sheet 2 Filed Oct. 2, 1943 INVENTOR. BY Lawn-ace H. Home A M, fiauml 'fiu Nov. 16, 1948. L. H. MORSE 2,453,927

CLAMP FOR MASTER SHEETS OF PRINTING MACHINES Filed Oct. 2, 1943 '3 Sheets-Sheet 3 LAWRENCE H. M K0) BY 42m, v 77 22.

Patented Nov. 16, 1948 CLAMP FOR MASTER SHEETS OF MACHINES PRINT-1N Lawrence H. Morse, Mentor, Ohio, assignor to Addressograph-Multigraph Corporation, Cleveland, Ohio, a corporation oi Delaware Application October 2, 1943, Serial No. 504,656 Claims. to]. 101-4151) This invention relates to a means for clamping one or more master sheets on a drum of a printing machine. One of the objects of the invention is to provide clamping mechanism which may take a. variety of master sheets, whether the same be metal or paper or other material, and whether they are provided with a. row of openings across one end (as is frequently the case) or have th end portion imperforate. My system provides such universal arrangement, both for the leading end of the sheet and the trailing end thereof, so that various forms of master sheets may be effectively clamped on the drum.

In carrying out my invention, I provide a clamp which may readily coact with the drum to clamp the end of a sheet between them and I also provide a. supplemental clamp coacting with the first clamp to clamp a sheet between the two clamps, whereby the first mentioned clamp serves the double function of clamping either with the drum or with the second clamp, according to the nature of the sheet to be clamped.

Another feature of my invention relates to means for clamping the trailing end of a comparatively short master sheet which is not long enough to reach the normal trailing clamp. To effect this I provide two swinging hooks which maybe idle within the drum or project beyond the same to pass through openings in such short master sheet adjacent the trailing end thereof to clamp the same. This feature allows the employment of a composite master composed of one sheet clamped by the normal clamp and a second sheet surmounting a portion of the flrst sheet and secured in part by one of the normal clamps and in part by my supplemental clamp.

,The features above outlined, and others contributing to the operation and efliciency of my clamping system, will be more apparent from the following detailed description of a, preferred embodiment illustrated in the drawings.

In the drawings, Fig. 1- is a plan of a' drum equipped with my novel master sheet clamp; Fig. 2 is an enlarged cross section of the same in an offset plane indicated by the line 2-2 on Fig. 1; Fig. 3 and Fig. 4 are fragmentary cross sections on the correspondingly numbered lines on Fig. 1, illustrating respectively different positions of the clamping apparatus; Fig. 5 is a fragmentary plan of the same scale as Figs. 2, 3 and 4, illustrating the clamping device adjacent one end thereof; Figs. 6 and "I are cross sections of the drum in an offset plane indicated by the line 8-'6 on Fig. 1, illustrating respectively different positions of the parts shown; Fig. 8 is a diagrammatic illustra- Ill tion ofwthe manner in 2 which one printing sheet maybe superposed on another.

In Figs. 1 to 7, l0 designates a suitable rotary drum having a segmental recess or'gap l I through its periphery. Adjacent one edge of the gap is a ledge adapted to form an anvil for the clamp to secure the leading edge of the sheet. .As shown in the drawings, this ledge is provided by a flat bar l5 secured in the radial position to the drum and having an outwardly facing longitudinal recess I6.

The clamping member for the leading end of the master sheet comprises a member 20 having a cross bar 2| longitudinal of the drum and a pair of end arms 22 pivoted on a shaft28 mounted in the drum. The end members 22 and the bracing longitudinal bar portion 2| carry a longitudinal strip 24 which is bent on itself to provide an inwardly extending flange 25 in position to coact with the groove 16. Two or more pins 26 (Fig. 4) carried by the bar l5 form suitable stops for the inner end of the sheet to be clamped on the drum. Springs 21 secured to the drum and to the arms 22 tend to maintain the flange 25 in coaction with the ledge I5 to deflect a very flexible sheet between them and effectively clamp it, as illustrated by the sheet designated A in Fig. 4.

I also secure to the cross bar 2| of this clamping yoke a face bar 28 having projecting pins or hooks 29 adapted to extend through openings in a master sheet.

The construction just described enables the mounting of the leading end of master sheets of various forms. If the sheet has a row of holes through it adjacent the end it may readily be hooked over the hooks 29. If the end portion of the sheet is imperforate, as is frequently the case with a paper sheet, it may be readily clamped by the flanged edge 25 which kinks the end portion of a sheet into the groove l6 as shown in Fig. 4.

To provide ready means to force the clamping member 22 backwardly away from the ledge l5,

I mo'iintin such clamping member a threaded sleeve 30 which carries a freely slidable rod 3| abutting the ledge l5. In a. bifurcated head 32 on the sleeve I mount a cam arm 34. When the clamping means provided by the flange 25 and the ledge I5 is to be idle, the clamping arm 34 is positioned outwardly in alignment with the rod 3 l, as shown in Fig. 3. This draws the clamping member 20 outwardly so that the flange 25 is well away from the ledge l5 as shown in Fig. 3.

I will now describe the clamp or clamps for the trailing edge 6! the'master sheet or sheets. As shown in various views I have mounted at the other edge of the gap in the drum a stationary clamping ledge 40 provided by a strip of material doubled on itself at an acute angle. One arm of this member extends radially and issecured by screws or otherwise to the radial face of the drum at the gap, while the other arm 4| extends as a chord in a direction across the gap of the drum. In this chordal face I make a series of openings corresponding in position to openings in the master sheet to be clamped and I provide a clamping member having inwardly projecting teeth to occupy such openings.

The clamping member above mentioned comprises a pair of end arms 50 and a cross plate having a reinforcing bar along its free edge portion, which bar has hooked teeth 53 adapted to extend through the openings in the face 4| of the anvil ledge. The arms 50 are provided with slots 55 which embrace the pins 56 projecting longitudinally inward from the end members of the drum, so that this clamping member is mounted both pivotally and slidably. A suitable spring tends to maintain the clamping member in its active or engaged position, and applies tension to the sheet in the act of clamping it.

I have shown for the above purpose a tension spring 56 anchored at one end to the clamping I member and at the other end to a collar 58 which for convenience is mounted on the shaft 23 heretofore mentioned. The direction of pull oi. the

spring 66 is such that it tends to maintain the clamp edge 52 in coaction with the anvil flange II and at the same time tends to pull such edge in a chordal direction inwardly of the drum. Accordingly, when a sheet is anchored at its leading end by one or the other of the means heretofore described, the clamp may be rocked outwardly to the position shown in Fig. 6, and the perforated trailing end of the sheet projected over the ledge 4 Thereupon the release of the clamp 50 will permit the springs 56 to return it to the position shown in Fig. '7. In moving to such position the clamp teeth 53 will readily pass through I the openings in the sheet, and, due to the sliding movement of the clamp on its pivot pins, the springs will cause the clamp to tension the sheet about the periphery of the drum.

I use the cross plate 5| of the main clampdescribed as an anvil for a supplemental clamp to engage a sheet which does not have the perforations for the teeth 53. As shown in several views suitable ears 59 of the main clamp 50 carry a cross rod 60. On this cross rod are pivotally mounted theflanged ends SI of a cross plate 82 which lies over the plate iii and is adapted to coact with it. A spring 65 coiled around the rod- 80 and anchored at one end to one of the ears 58 and at the other end bearing against the plate 62 tends to maintain the plate 62 in engagement with the :plate 5|. The innermost edge of the plate 62 is curled outwardly and backwardly over the rod 60 to provide a finger grip 61.

The spring is materially lighter in its action than the spring 56 so that if the operators finger is applied to the ledge 61 as indicated in Fig. 3, the plate 62 may be swung away from the anvil plate 5| to provide an opening for the insertion of an imperforate plate. Then when the finger pressure is removed the spring 55 will return the surmounting plate into the position shown in Fig. 4 to clamp the sheet, indicated at A, between them. I prefer to make recesses 51 and complementary projections 68 on the two plates SI and 82 to indent or perforate the end portion of a normally imperforate paper plate which may be clamped between the members thus insuring a tight engagement.

To prevent any looseness or indefiniteness in the action I prefer to lock the main clamp to the drum when the supplemental clamp is to be actuated, and conversely to lock the two clamps toare a pair of latch arms I0 each pivoted at II and normally held in either extreme position by a leaf spring 12 engaging either of two flat faces at an angle to each other on the arm back of the pivot. Each arm in one extreme position, as shown in Fig. 1, may lie beneath the inwardly projecting end of the corresponding pin 54 which form the pivotal mounting for the clamp. Such position causes an upright shoulder I3 on the latch lever to stand in front of the pin thereby maintaining the clamp ill in closed position while leaving the supplemental clamp free. With the latches 10 in this position as shown in Fig. 1, the main clamp is idle and the finger pressure on the ledge 61 operates merely the supplemental clamp 62. a

If, however, the latches Ill are thrown over to their other extreme position, as shown in Fig. 5, they free the main'clamp from the pin 54 and at the same time, by sliding beneath the projecting tongues 68 on the plate 62 lock the two clamping plates together as shown in Fig, 5. With the latches in this position the finger pressure on the ledge 61 will operate to raise the clamping bar 5| from the drum anvil 4| of the main clamp. It is frequently desirable to skew the master sheet slightly after it is mounted on the drum to true up the image in'case it is not strictly parallel with the side edges of the sheet, or in case the clamped end of the sheet is notabsolutely at right angles to the sides. To provide for this, I mount in the arms 22 of the leading clamp a longitudinal rod threaded in one of such arms and its ends abutting the inner surface of the end members of the drum. A suitable knurled collar 8| on this rod furnishes ready means for rotating it in either direction to shift the clamp correspondingly a short distance, if necessary for accurate presentation of the image.

The hooks 29 of the leading clamp and the hooks 5| of the main clamp at the trailing end may readily mount on the drum a sheet having a row of openings across its ends as indicated by the sheet B in Fig. 8. For some uses, however, it is desirable to employ a short supplemental master sheet overlying the sheet B. Such a supplemental sheet is shown at C in Fig. 8. It may readily have a length somewhat greater than the width of the sheet B and is so shown. This supplemental sheet has a pair of openings 0 through it adjacent its trailing end and my machine provides a pair of hooks adapted'to be forced into position in. the openings whenever desired to clamp the trailing end of such sheets. This mechanism will now be described with particular references to Figs. 1, 2 and '7.

I mount rotatably in the drum a shaft naidly carrying a pair of rock arms 8| formed with outward hooks 92. A spring 93 coiled about the shaft and anchored at one end to one of the arms 1 and at the other end to the drum tends to swing the arm into the position shown in Fig. 2, where they are entirely idle within the periphery of the drum and at the end oi arcuate slots 95 in the drum which are occupied by the hooked arms. AL the external end of the shaft 90 I provide a thumb segment 81 shown in Fig. 1 and indicated in broken lines in Fig. 2.

. into binding position where the hook members 92 overlie the face of the supplemental sheet Cbeyond the range of the member to coact therewith, be it a 'platen for direct printing or a blanket for offset printing;

I have referred to the short sheet C as a supplemental sheet surmounting another master sheet. It is to be bornein mind, however, as will be readily understood, that the sheet C may be used without the sheet B ifthere is occasion therefore. Furthermore, the sheet C may not be as short as shown in Fig. 8 but may extend beyond the openings 0 and still be effectively held in place by the hooks passing through such opens ings.

It will be seen that my clamping system is practicaily universal for all sorts and types of sheets to be fastened. The sheets may be of metal or of paper; they may have openings along their ends or such end portions may be lmperforate. The projecting hooks provide ready means for engaging any sheet provided with properly spaced openings. If, however, the sheet has no openings and relies merely on a bending or kinking of the edge portion of the sheet, which may be very effective with light paper sheets, then the clamping means provides for that condition. Furthermore, the clamp for the non-perforate sheet may be readily thrown to idle position whenever desired so that the main clamp for the perforated sheets can be operated withoutregard to the supplemental clamp. Likewise when the supplemental clamp is used the main clamp is efiectively held in idle position so as not to interfere with the action of the supplemental clamp,

Notwithstanding the independence of the two clamping actions, they are consolidated into one composite clamp by the novel characteristic of employing the clamping member of one clamp as the anvil for the other clamp. At the leading end the clamping member makes the anchorage for the perforate sheet. At the trailing end the clamping member for the perforated sheet forms the anvil for the clamp for the non-perforated sheet.

It should be noted also that the supplemental clamp for the short master sheet, shown as ooacting with the sheet held by the main clamps, may be used with sheets held by the clamp for imperforate masters. If the sheet C is of metal it will ordinarily be formed with openings 0 through it. If it is of paper, the openings may be pre-formed or punched through the sheet by the projecting hooks themselves. That is to say, the hooks 92 may be turned out into a position beyond the periphery of the drum but not reaching the final position and then the sheet pressed onto such projecting hooks until the hooks pass through the sheet, after which the spring 93 will swing the hooks into a position shown in Fig. 7 to clamp the sheet.

Iclaim: V 1 1. The combination of a rotary drum having a ledge to form an anvil for a sheet, a pivoted clamping member mounted in the drum having an edge adapted to coact with the ledge to clamp a sheet between them, a sleeve threaded in the clamping member, a slidable rod mounted in the sleeve adapted to coact with the drum, and a camming arm carried by the sleeve and adapted to coact with the rod to force the clamping member into idle position with reference to a clamping ledge on the drum. r

2. The combination of a printing drum, means for clamping a master sheet thereon and for holding the leading edge ofa supplemental master sheet over the first master sheet, said supplemental master sheet having openings through it 0 -adjacent its edges, said drum having a pair of hooks adapted to extend beyond the periphery of the drum and pass through said openings, and spring means acting on the hooks to lock the engaged portion of the supplemental master sheet to the drum.

3. The combination of a rotary drum havin a ledge to form an anvil, a pivoted clamping member mounted in the drum'and having an edge adapted to coact with the ledge to clamp a sheet between them, a rod siidablymounted in the pivoted member and adapted to abut a stop on the drum, and a cam 'carried by the pivoted member and adapted to shove the rod axially toward the ledge and thereby move the clamping edge away from the anvil.

4. The combination of a printing drum having a gap, a ledge carried by the drum within the gap, a pivoted member in the drum having a portion to coact with said ledge to clamp a sheet between them, a row of pins on the pivoted member projecting outwardly and also ina direction away from the'adjacent edge of the gap to provide hooks adapted to form an anchorage for a sheet having a row of holes across its end, a spring tending to maintain said pivoted member seated against the ledge, and means for moving the pivoted member in opposition to the spring.

5. The combination of a. drum adapted to carry a master sheet, a clamp thereon for holding the leading end of said sheet, said clamp being adapted also to hold the leading end of asurmounting supplemental sheet wider than the main master sheet, and means on the drum adapted to'en gage such supplemental master sheet beyond the side edges of the main master sheet for retaining the free end of the supplemental sheet without obstructing the uncovered portion of the main master sheet.

6. The combination of a drum having agap,

thereby retaining the free end thereof.

7. The combination of a drum having a gap, means within the gap for holding the leading ends of a main master sheet and a. surmounting wider supplemental master sheet, and holding means carried by the drum adapted to engage aasapa'r trailing portions of the supplemental sheet beyond the marginal edges or the main master sheet.

8. The combination of a drum having cylindrical surface with a gap. a pair of clamps within the gap adapted respectively to engage the leading and and the trailing end of a main master sheet embracing said cylindrical surface, and

.means carried by the drum circumferentially between said two clamps and adjacent the ends oi.

the drum and adapted to extend radially beyond.

the cylindrical surface of the drum for engaging only a side margin of a shorter supplemental master sheet surmounting the main master sheet.

9. The combination of a drum having a cylindrical surface with a gap, means in the gap for clamping a master sheet and a surmounting supplenfental master sheet across the leading ends or the sheets, and a retaining device movably 8 means in the gap for clamping said sheets across their leading ends, a pair of hooks pivotally mounted within the drum, said hooks being adapted to lie entirely within the drum or to extend radially beyond its cylindrical surface through arcuate openings through said cylindrical surface of the drum adjacent its ends leaving the cylindrical surface uninterrupted between the arcuate openings, and spring means acting on the hooks and tending to swing them in a direction away from the clamping means for the leading end to apply tension to the supplemental sheet adj acent its trailing end.

LAWRENCE H. MORSE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,607,386 Brasseur Nov. 16, 1926 1,913,392 Jacobson June 13, 1933 2,012,972 Osborn Sept. 3, 1935 2,021,894 Morse Nov. 26, 1935 2,088,862 Lang Aug. 3, 1937 2,165,233 Curtis July 11, 1939 2,296,533

Neal Sept. 22, 1942 

